Coordinate transformer for transforming control signals in airplanes

ABSTRACT

The disclosure is of a coordinate transformer for transforming control signals for airplanes, particularly for transforming Cartesian input signals into polar output signals, which have, in addition to a thrust control element, a thrust direction control element or operating member for controlling the thrust components and for uncoupling control axles. This is achieved by the use of two multi-sectional coupling gears or linkages, one linkage determining therein the distance r, while the other linkage determines the respectively coordinated angle Alpha toward the polar axis from the two Cartesian x-y input signals.

United States Patent [191 Stauber et al. [4 1 Jan. 9, 1973 [54]COORDINATE TRANSFORMER FOR [56] References Cited TRANSFORMING CONTROLSIGNALS UNITED STATES PATENTS IN AIRPLANES g 2,338,379 l/l944 Henke..244/83 C' 3,199,601 8/l965 Dean etal. Invemors= Siegfried wemgarten;3,327,552 6/1967 Broders 8t 3|. ..74/469- Klaus Suttner, Stetten, bothof Ger- I y Primary Examiner-Milton Kaufman Attorney-James E. Bryan [73]Assignee: Dornier A. G., Friedrickafen/Bodensee Germany [57] ABSTRACTThe disclosure is of a coordinate transformer for [22] Filed: Jam 18,1971 transforming control signals for airplanes, particularly fortransforming Cartesian input signals into polar output signals, whichhave, in addition to a thrust control [21] Appl. No.: 107,100 element, athrust direction control element or operating member for controlling thethrust componentsand for uncoupling control axles. This is achieved bythe Forelgn Apphcaflon Priority Dam use of two multi-sectional couplinggears or linkages, Feb 27 1970 Germany ..P 2009 145.6 linkagedetermining herein the distance While the other linkage determines therespectively coors2 U.S.Cl.. .....74/469, 74/479, 244/83 B gggf gf ifgrg z Imam fmm 51] rm. Cl. ..G05g 1/04 y P g Field of Search ..74/469,479; 244/838, 836

2 Claims, 2 Drawing Figures PATENTEDJAN 9:975 3.709.056

sum 10F 2 INVENI'OIS SIEGFRIED STALBER KL AUS SUTTNER PATENTEDJAN 9 I975I 3, 709,056

SHEET 2 Hi2 FIG. 2

INVEN'IOIS SIEGFRIED STPUBER KLAUS SUTTNER ATTOII N BY COORDINATETRANSFORMER FOR TRANSFORMING CONTROL SIGNALS IN AIRPLANES The presentinvention relates to a coordinate transformer for the transformation ofcontrol signals in aircraft, particularly for transforming Cartesianinput signals into polar output signals, which have, in addition to athrust control element or operating member, a thrust direction controlelement for regulating the thrust components and for uncoupling controlaxles.

Coordinate transformers serve for transforming or converting controlsignals which are fed into airplanes according to the Cartesiancoordinate system but are intended to execute movements according to thepolar coordinate system. Without the presence of a coordinatetransformer, the pilot would have to assume the function of the formerby means of an alternating gradual switching-on of the control signalcomponents. When a coordinate transformer is used, on the other hand, aconstant control signal may be derived or received at once in the polarcoordinate system.

It is known that it is possible to carry out a coordinate transformationwith the aid ofa coordinate table and a tapping arm. The coordinatetable consists of two crosshead guides having a cylindrical shape, forexample, which are positioned parallel with respect to each other andrigid with regard to the frame. A slide travels thereon which carries acrosshead guide at a right angle to itsdirection of movement. Positionedat a right angle to this first system and in a plane thereabove is asecond similar system. The point of intersection of the crosshead guidesof the two systems on the slide serves as a coordinate point in theCartesian system, and the individual movements serve as input signals inthe x-y direction. The position of the point of intersection may betapped as an output signal in polar coordinates when a tapping arm isprovided for as a connection from this point ofintersection to thecoordinate origin. The point of intersection is formed by a slide ringwhich is common to both crosshead guides and which will come to bepositioned at its point corresponding respectively to the mathematicalcoordination thereof. This arm is positioned in the coordinate origin;it is adapted to be extended and retracted telescopically and representsboth the distance r from the coordinate origin and the angle to thecoordinate abscissa. In order to achieve an actuation which is as devoidof force as possible, the slides of the coordinate table are driven byway of hydraulic amplifiers.

Also known is a coordinate transformer which drives the coordinate tablewith the aid of cables rather than by means of hydraulic poweramplifiers. The positive drive is obtained by means of doubly providedcables. It is disadvantageous in this case that it is not possible tocover the entire field if, for example, a signal for a propulsion unitis involved which is not to fall below a specific value.

Furthermore, there exists the danger of coupling; in other words, thedanger that both axles or shafts are actuated at the same time. In orderto obviate this disadvantage regarding coupling effects, it is necessaryto provide fur further structural elements, such as an excess pressuremember. In the case of the use of cables, the actuation is additionallyrendered difficult due to friction of the many reversing rollers.

Those skilled in the art therefore began to bypass the disadvantages anddrawbacks of the gear systems referred to hereinabove by making use of aspatial cam gear as the coordinate transformer. Most suitable for thetechnical execution thereof are controller cylinders or drums which arenot only rotatable about the iongitudinal axis thereof but displaceableas well. Required for the formation of the polar coordinates are onecylinder or roller for the angle, and one for the distance or clearanceand having a common drive. The cylinders or rollers are scanned in eachcase by a scanning member, and the respective position thereof istransmitted to a hydraulic amplifier. This amplifier is necessary inorder to keep the manual forces as small as possible. In order that apositive drive or guided motion be achieved, a synchronously operatingcounter cylinder or roller is coordinated to each of the two cylindersor rollers. In the clearance between the two cylinders or rollers, whichhas if possible the same width in all positions, there extends andoperates a scanning member in a manner such that both rollers orcylinders are touched simultaneously.

It is also known to use planar lever gear systems for coordinatetransformers. These lever gear systems consist of a plurality ofindividual gear systems which individually execute each mathematicalstep. If a coordinate transformer is designed and plotted according tothe signal flow sheet, a great number of individual gears are necessarytherefor. One must provide for a gear unit which forms the square of acomponent; a further gear unit for the second component; a gear whichforms the radical function, as well as a gear which forms the ratio 1:1/r. Added thereto is a control gear which executes the multiplication,and finally a gear which forms or constitutes the sine function withrespect to the coordinated angular value. In order to render it possibleto fully drive this number of gear systems or units, two hydraulicamplifiers are required. This, in turn, results in an increased weight.It is most unfavorable in this case that for a mathematical addition, adifferential lever is necessary which may cause a regenerative coupling.While a coordinate transformer of this type fully satisfies therespective requirements, it has the significant disadvantage that thecontrol signal must pass through a considerable number of gear systemsor units. The danger that the control paths be falsified due toelasticity, clearance and friction is rather great.

The present invention provides a coordinate transformer for transformingcontrol signals for airplanes, particularly for transforming Cartesianinput signals into polar output signals, which have, in addition to athrust control element, a thrust direction control element or operatingmember for controlling the thrust components and, for uncoupling controlaxles.

This is achieved, in accordance with the present invention, by virtue ofthe use of two muIti-sectional coupling gears or linkages; one linkagedetermining therein the distance r, while the other linkage determinesthe respectively coordinated angle 0: toward the polar axis from the twoCartesian x-y input signals. Because of the use of the linkages, thereresults a coordinate transformer which carries out the transformation ofthe coordinates in a completely controlled manner, and free of any play.

. Applying the present invention to a VTOL aircraft, for the verticaltake-offand landing phase, as well as for the transitional flight fromvertical flight to horizontal flight, two factors are particularlyimportant, namey.

1. the power unit or engine thrust and 2. the thrust direction of thepower units or engines.

Two separateoperating levers were formerly provided for these twofactors. This'resulted, however, in a very large workload for the pilot,who was required to continually reach over from one lever to the otherand make corresponding adjustments. Since the starting and landingphases, as well as the transitional flight, require the full andundivided attention of the pilot, the object sought to be obtained inthe present invention is to relieve the pilot of the workload as much aspossible. For this reason, it was attempted, for example, to act uponthe two aforementioned factors, i.e., the thrust and the thrustdirection, by means ofa common operating lever. This is attained, forexample, by virtue of the fact that the control stick is mounted so asto be adapted to be inclined in all directions, so as to be displaceablein a Cartesian coordinate system. In this case, one coordinate isassigned to the thrust direction,'and the other coordinate is assignedto the thrust intensity.

In actual practice, it has been found necessary to act upon the memberto be regulated or adjusted, for example a lift engine,in the form ofpolar coordinates. This isbased uponthe fact that the thrust may beassumed or conceived to be a vector, whereby the length of the vector rcorresponds to the intensity of the thrust, and wherein the direction ofthe vector r indicates the angle of emergence of the power jet, i.e.,the thrust direction. It is, therefore, advisable to displace themechanical device for. varying the thrust direction, for example pivotalnozzles, about an angle a and to regulate the intensity of the thrust atthe throttle by the amount r of the vector.

The present invention provides a gear system which renders possible on amechanical basis the conversion of quantities of magnitudes existing inthe Cartesian coordinate system into a polar coordinate system, in whichsufficiently high displacement or setting forces can be taken off at theoutput of the gear.

The present invention will be more fully described hereinafter on thebasis of one embodiment thereof and taken in connection with theaccompanying drawing, wherein FIG. 1 is a schematic representation of acoordinatetransformer; and FIG. 2 shows the double provision of acoordinate transformer.

In FIG. 1, a coordinate transformer is schematically illustratedtherein. The linkage 1 forms from the two Cartesian x-y input signalsthe distance r,,and the other linkage 2 forms the coordinated angle 01against the polar axis. The y-input signal member 3 normallyacts upon arocker'arm orlever arm 4 being mounted in a suspended fashion at theframe 32 with a bearing axle 16. The end point 5 of the rocker arm 4 isconnected by way of a couple 6 with a further counter rocker arm 7 whoseother end is, in turn, mounted at the frame 32.

Secured approximately in the center of the counter rocker arm or leverarm 7 and normal with respect thereto is a double lever 9 by means ofbearings 8. The x-input signal member 10 acts by way ofan angle ortoward the polar axis. This gear part is therefore designated as a gear.

Mounted at the bearing axles 16 and 22 to which latter the rocker arm 4,on the one hand, and the angle or toggle lever 12, on the other hand,are rotatably secured, inthe extension of the axial lines, is a shafteach 30 and 31 which serve as drives for the second linkage 2. Thesecond linkage serves as the square part of the gear system and consistsfirst of all of a rocker arm 17 and/or 17' which is positionedapproximately normal with respect to the position of therocker arm orlever 4 and rigidly connected with the shaft 30 and/or 31. In theextension of the rocker arm 17 and/or 17, one couple each 18and 18', ishingedly connected with the other ends thereof via another double lever19 to the bearing ends 20 and/or 21. With the bearing 24 the doublelever 19 is mounted at a rocker or lever arm 23. I

This lever 23 is in an approximately parallel position with respect tothe double lever 19. The other end of the rocker arm or lever 23, inturn, is mounted at the frame 32. Additionally connected at the bearing24 ap' proximately parallel to the coupling rods 18 and 18 is an excesspressure member 25. Mounted adjoining the 7 already received at theoutput side of the angle lever 26 and corresponds to the distance r ofthe polar coordinate system.

This gear system follows themathematical equation and a arc tan y/xAccordingly, the movements of the x-y input signals are converted in thelinkage 1 into angular values against the polar axis. This gear systemrepresents the mathematical function of the a gear unit or system. Thelinkage 2 consists of the square parts, an adding part or portion, aswell as the adjacent radial portion in which the distance r isdetermined.

It is apparent from FIG. 2 that the coordinate transformer also may beconstructed as a dual coordinate transformer. In this case, the linkage.1, 2 may be used for the yaw control and for.the horizontalacceleration via the lever systems 3, 10, 27 and 28. The other link-vage I', 2" serves for the rolling control and for the verticalacceleration via the lever systems 3a, 10a, 27a,.and 28a. It isunderstood that this arrangement may be, further expanded and used foraircraft with several thrust producing means. In the latter case, thethrust producing means may be controlled independently with respect toeach other for control or navigating purposes.

By virtue of the construction of the coordinate transformer of thepresent invention, it has been rendered possible that each pilot is ableto feed in Cartesian control signals but will obtain the signals in thepolar coordinate diagram over the entire field. The advantages resideparticularly in that a very wide control range is rendered possible withthe aid of the invention. Tests have shown that the pivot angle mayextend from 0 to 150. The deviations from the mathematical relation thatmay still arise are very small in view of the fact that the two gearparts are driven by the unfalsified input signals x and y and are fullycompensated by the aerodynamic lift, As a further area of application,the coordinate transformer may be employed for uncoupling the steeringmechanism, for example the rolling and the yaw axes, as well as theaccelerating axes.

It will be obvious to those skilled in the art that many modificationsmay be made within the scope of the present invention without departingfrom the spirit thereof, and the invention includes all suchmodifications.

What is claimed is: I 1. In a coordinate transformer for transformingcontrol signals for aircraft, particularly for transforming Cartesianinput signals into polar output signals which aircraft have, in additionto a thrust control element, a thrust direction control element forcontrolling thrust components and uncoupling control axles,

the improvement which comprises first and second muIti-sectional linkagemeans connecting a control means adapted to be actuated by a pilot and asource of thrust, one of which linkage means determines the distance r,and the other of which determines the coordinated angle 0: towards thepolar axis from the two Cartesian x-y input signals,

said first linkage means including a y-input signal member connected toa first rocker arm mounted in a suspended manner on a frame,

coupling means connecting the end of the first rocker arm with a secondcounter rocker arm, first double lever means mounted on the counterrocker arm, I

x-input signal means acting at one end of the double lever means throughan angle lever means and a coupling means,

means connected at the other end of the double lever I means formeasuring the angle with respect to the polar axis as an output member,and I said second linkage means including a third rocker I arm mountedon a shaft supporting said first rocker arm, the said rocker arms beingmounted normal to each other,

one end through a coupling means to the end of the third rocker arm, andthe other end of said second double lever means being connected througha coupling means to a fourth rocker arm on a shaft supporting the anglelever means through which the x-input signal means acts, said seconddouble lever means being supported in the center thereof by bearingmeans on a fifth rocker arm which is approximately parallel to thesecond double lever means, angle lever means acting through an excesspressure member at the bearingmeans, and linkage means connected to saidangle lever means, the setting value of the output movement of thelatter linkage means corresponding to the distance I. 2. A coordinatetransformer according to claim 1 including at a first linkage means, ay-input signal member connected to a first rocker arm mounted in asuspended manner on a frame,

coupling means connected the end of the rocker arm.

with a second counter rocker arm,

first double lever means mounted on the counterrocker arm, x-inputsignal means acting at one end of the double lever means through anangle lever means and'a coupling means,

means connected at the other end of the double lever means for tappingthe angle toward the polar axis of an output member,-

a third rocker arm mounted on a shaft supporting th first rocker arm,the said rocker arms being mounted normal to each other,

second double lever means hingedly connected to one end through acoupling means to the end of the third rocker arm, and the other end ofsaid second double lever means being connected through a coupling meansto a fourth rocker arm on a shaft supporting the angle lever meansthrough which the x-input signal means acts, said second double levermeans being supported in the center thereof by bearing means on a fifthrocker arm which is approximately parallel to the secon double levermeans,

angle lever means acting through an excess pressure member at thebearing means, and

linkage means connected to said latter angle lever means, the settingvalue of the output movement of the latter linkage means correspondingto the distance r.

second double lever means hingedly connected at

1. In a coordinate transformer for transforming conTrol signals foraircraft, particularly for transforming Cartesian input signals intopolar output signals which aircraft have, in addition to a thrustcontrol element, a thrust direction control element for controllingthrust components and uncoupling control axles, the improvement whichcomprises first and second multi-sectional linkage means connecting acontrol means adapted to be actuated by a pilot and a source of thrust,one of which linkage means determines the distance r, and the other ofwhich determines the coordinated angle Alpha towards the polar axis fromthe two Cartesian x-y input signals, said first linkage means includinga y-input signal member connected to a first rocker arm mounted in asuspended manner on a frame, coupling means connecting the end of thefirst rocker arm with a second counter rocker arm, first double levermeans mounted on the counter rocker arm, x-input signal means acting atone end of the double lever means through an angle lever means and acoupling means, means connected at the other end of the double levermeans for measuring the angle with respect to the polar axis as anoutput member, and said second linkage means including a third rockerarm mounted on a shaft supporting said first rocker arm, the said rockerarms being mounted normal to each other, second double lever meanshingedly connected at one end through a coupling means to the end of thethird rocker arm, and the other end of said second double lever meansbeing connected through a coupling means to a fourth rocker arm on ashaft supporting the angle lever means through which the x-input signalmeans acts, said second double lever means being supported in the centerthereof by bearing means on a fifth rocker arm which is approximatelyparallel to the second double lever means, angle lever means actingthrough an excess pressure member at the bearing means, and linkagemeans connected to said angle lever means, the setting value of theoutput movement of the latter linkage means corresponding to thedistance r.
 2. A coordinate transformer according to claim 1 includingat a first linkage means, a y-input signal member connected to a firstrocker arm mounted in a suspended manner on a frame, coupling meansconnected the end of the rocker arm with a second counter rocker arm,first double lever means mounted on the counter rocker arm, x-inputsignal means acting at one end of the double lever means through anangle lever means and a coupling means, means connected at the other endof the double lever means for tapping the angle toward the polar axis ofan output member, a third rocker arm mounted on a shaft supporting thefirst rocker arm, the said rocker arms being mounted normal to eachother, second double lever means hingedly connected to one end through acoupling means to the end of the third rocker arm, and the other end ofsaid second double lever means being connected through a coupling meansto a fourth rocker arm on a shaft supporting the angle lever meansthrough which the x-input signal means acts, said second double levermeans being supported in the center thereof by bearing means on a fifthrocker arm which is approximately parallel to the second double levermeans, angle lever means acting through an excess pressure member at thebearing means, and linkage means connected to said latter angle levermeans, the setting value of the output movement of the latter linkagemeans corresponding to the distance r.
 3. A coordinate transformeraccording to claim 1 including a limit stop mounted at the last-namedangle lever means.